Differences in Nitrogen Efficiency among Different Kinds of Fast-growing Eucalyptus Seedling
Response to nitrogen from different kinds of Eucalyptus seedlings were studied for screening Eucalyptus varieties with high nitrogen efficiency. Greenhouse experiments in Guangxi Academy of Agricultural Sciences were carried out to understand the response under two nitrogen levels in 2009. The results showed:(i)Under normal nitrogen, there were significant variations in total N uptake (TNU) , N uptake efficiency (NUE) , N physiological utilization efficiency (NPE) , and N use efficiency (NE) as well among the five Eucalyptus genotypes. Any of them could be considered as referential index to select high NE Eucalyptus genotype. The differences of NE were determined principally by TNU and NUE. (ii)The tested Eucalyptus could be classified into three different types based on NE: urophylla ×camaldulensis belonged to HH type (high N use efficiency at high nitrogen level); No.4 Guanglin E. urophylla and E. urophylla×E. grandis belonged to HM type ( mid N use efficiency at high nitrogen level) ; No. 12 Guanglin E. grandis X E. urophylla and No. 9 Guanglin E. grandis × E. urophylla belonged to HL type (low N use efficiency at high nitrogen level). The basis for breeding the high NE Eucalyptus variety at low N level or at both low and high N level conditions could be provided by the Eucalyptus of HH type or HL type. (iii)Dry plant weight, dry root weight, dry branch and leaf weight, TNU, NUE, and nitrogen responsiveness were significantly correlative with NE, so all of them could be regarded as the indexes to screen the variety with high NE.
NETL
NSTL
万方数据
维普
